<?php
/**
 *  $Id$
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 * Doctrine_Locator_Injectable
 *
 * @package     Doctrine
 * @subpackage  Doctrine_Locator
 * @category    Locator
 * @license     http://www.gnu.org/licenses/lgpl.txt LGPL
 * @link        http://www.doctrine-project.org
 * @author      Janne Vanhala <jpvanhal@cc.hut.fi>
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author      Eevert Saukkokoski <dmnEe0@gmail.com>
 * @version     $Revision$
 * @since       1.0
 */
class Doctrine_Locator_Injectable
{
	/**
	 * @var Doctrine_Locator      the locator object
	 */
	protected $_locator;

	/**
	 * @var array               an array of bound resources
	 */
	protected $_resources = array();

	/**
	 * @var Doctrine_Null $null     Doctrine_Null object, used for extremely fast null value checking
	 */
	protected static $_null;

	/**
	 * setLocator
	 * this method can be used for setting the locator object locally
	 *
	 * @param Doctrine_Locator                the locator object
	 * @return Doctrine_Locator_Injectable    this instance
	 */
	public function setLocator(Doctrine_Locator $locator)
	{
		$this->_locator = $locator;
		return $this;
	}

	/**
	 * getLocator
	 * returns the locator associated with this object
	 *
	 * if there are no locator locally associated then
	 * this method tries to fetch the current global locator
	 *
	 * @return Doctrine_Locator
	 */
	public function getLocator()
	{
		if ( ! isset($this->_locator)) {
			$this->_locator = Doctrine_Locator::instance();

		}
		return $this->_locator;
	}

	/**
	 * locate
	 * locates a resource by given name and returns it
	 *
	 * if the resource cannot be found locally this method tries
	 * to use the global locator for finding the resource
	 *
	 * @see Doctrine_Locator::locate()
	 * @throws Doctrine_Locator_Exception     if the resource could not be found
	 * @param string $name                  the name of the resource
	 * @return mixed                        the located resource
	 */
	public function locate($name)
	{
		if (isset($this->_resources[$name])) {
			if (is_object($this->_resources[$name])) {
				return $this->_resources[$name];
			} else {
				// get the name of the concrete implementation
				$concreteImpl = $this->_resources[$name];

				return $this->getLocator()->locate($concreteImpl);
			}
		} else {
			return $this->getLocator()->locate($name);
		}
	}

	/**
	 * bind
	 * binds a resource to a name
	 *
	 * @param string $name      the name of the resource to bind
	 * @param mixed $value      the value of the resource
	 * @return Doctrine_Locator   this object
	 */
	public function bind($name, $resource)
	{
		$this->_resources[$name] = $resource;

		return $this;
	}

	/**
	 * initNullObject
	 * initializes the null object
	 *
	 * @param Doctrine_Null $null
	 * @return void
	 */
	public static function initNullObject(Doctrine_Null $null)
	{
		self::$_null = $null;
	}

	/**
	 * getNullObject
	 * returns the null object associated with this object
	 *
	 * @return Doctrine_Null
	 */
	public static function getNullObject()
	{
		return self::$_null;
	}
}